[英]Swift: Issue accessing key in nested dictionary
我在访问嵌套字典中的键时遇到问题。
在我的ViewDidLoad中,我定义了字典(currentDots)来存储字符串键和任何对象作为值:
ViewDidLoad
var currentDots = Dictionary<String, Any>()
在这里,它正在侦听回调中的对象,并将字典写入currentDots字典。没问题,可以正常工作:
查询处理程序
func setupQueryHandle(query: GFCircleQuery) {
var queryHandle = query.observeEventType(GFEventTypeKeyEntered, withBlock: { (key: String!, location: CLLocation!) in
var dotRef = firebaseReference.childByAppendingPath("dotLocation/\(key)")
dotRef.observeEventType(.Value, withBlock: { snapshot in
self.currentDots[key] = ["name": snapshot.value.objectForKey("dot_name") , "description": snapshot.value.objectForKey("dot_description"), "range": snapshot.value.objectForKey("range"), "location": location ]**
self.annotateDot(key)
}, withCancelBlock: { error in
println(error.description)
})
})
}
但是在这里,我无法解析Dictionary中的键,尽管以上语句将字典作为Dictionary对象编写,但编译器会跳过if temp是Dictionary语句:
注释点
func annotateDot(key: String) {
if currentDots[key] as Any? != nil {
let temp = currentDots[key]!
println("Current dot is... \(temp)")
if temp is Dictionary<String,Any> {
println(currentDots[key]!)
let dotDictionary = currentDots[key] as Dictionary <String, AnyObject>
let dotName = dotDictionary["name"] as String
println(dotName)
}
}
}
我在“ if”语句之前获得的println(“ Current dot is”)输出:
403986692:[范围:可选(500),描述:可选(这是一个测试点!),名称:可选(mudchute DLR),位置:可选(<+ 51.49173972,-0.01396433> +/- 0.00m(速度-1.00) mps / course -1.00)@ 17/12/2014 15:12:09 Greenwich Mean Time)],
建议在currentDots [403986692]上进行查找的..只会返回字典,而不会。 当我遍历temp对象时,在Xcode中显示为正在键入:
([String:protocol <>?])
有人知道我在做什么错吗? 您的帮助将不胜感激。
谢谢!
尝试更改currentDots
的声明,因为我认为问题的一部分与您将Any
可选项有关,这并不是一个好主意:
var currentDots = Dictionary<String, AnyObject>()
然后尝试对annotateDot(key: String)
:
func annotateDot(key: String) {
if let dot = currentDots[key] as? Dictionary<String, AnyObject> {
// This for the name ...
if let name = dot["name"] as? String {
println("=== \(name) ===")
}
// ... or this to print all keys
for (key, value) in dot {
if key != "name" {
println ("\(key) : \( value )")
}
}
}
}
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